WASHINGTON -- After this winter of his discontent, the president needs Spring Training. He is far from midseason form, and his accumulating errors are undermining the premise of his re-election campaign, which is: Wartime demands hard choices and sacrifices, and a president who is steady, measured and believable.

Rhetorical carelessness and overreaching began before the war, when various administration officials ignored Mark Twain's warning that the difference between the right word and almost the right word can be the difference between lightning bug and lightning. It would have been much better if the president and others, speaking about Iraqi weapons, had said ``we believe'' rather than ``we know.''

After the war, in May, on Polish television, President Bush said, ``We found the weapons of mass destruction. You know, we found biological laboratories.'' No, we did not. ``So what's the difference?'' said the president in December about the failure to find WMDs, because ``if (Saddam) were to acquire weapons, he would be the danger.'' Such casualness, which would be alarming in any president, is especially so in one whose vaulting foreign policy ambitions have turned his first term into Woodrow Wilson's third term, devoted to planting democracy and ``universal values'' in hitherto inhospitable places.

Once begun, leakage of public confidence in a president's pronouncements is difficult to staunch. This president's certitude that $400 billion ``is enough to meet our commitments'' for 10 years under the new Medicare prescription drug entitlement was followed by a one-third upward revision of the estimate. Especially dismaying was that the fact that the president seemed not to know -- or, worse, care -- that an inherent problem with vast welfare state expansions is that no one can know crucial variables, such as, in this instance, the number of people choosing to participate and the coming menu of new drugs.

Republicans are swiftly forfeiting the perception that they are especially responsible stewards of government finances. It is surreal for a Republican president to submit a budget to a Republican-controlled Congress and have Republican legislators vow to remove the ``waste'' that he has included and that they have hitherto funded.

The president does indeed propose killing 65 programs and substantially curtailing 63. But even if Congress fully complies, which it won't, the savings would be just $4.9 billion -- a rounding error in a $2.4 trillion budget. That $4.9 billion would pay less than six days' interest on the national debt.

Two post-1945 elections -- one a landslide, one a cliffhanger -- produced dramatic spending surges. Lyndon Johnson's 1964 rout of Barry Goldwater created in Congress the first liberal legislating majority since 1938. Pent-up liberal demands produced, among much else, Medicare. There is no such obvious explanation for the spending surge since 2000, other than the possibility that deficits are one way ``compassionate conservatism'' defines itself.

One reason for wanting Bush to win a second term is that the 22nd Amendment, by precluding third terms, makes some matters ``second term issues'' -- those too difficult to address while seeking re-election. In the last year of Bush's second term, or of John Kerry's first, the first of 77 million baby boomers will begin to retire, and to bankrupt Social Security and Medicare as currently configured.

Bush, unlike Kerry, has admirably bold plans for meeting these predictable crises, which are his generation's greatest domestic challenges. But these plans involve complexities and responsibilities that the public will fathom and accept only if they are explained by a president whom the public believes speaks judiciously and knows things, including what he does not know.

Furthermore, this president's plan for reforming Social Security, which involves allowing individuals to invest a portion of Social Security taxes in approved private accounts, will have large transition costs. Large deficits of the sort currently occurring may become a reason, or at least an excuse, for further delaying reform.

So far, the president's difficulties have been partially obscured by the sheer silliness of the Democrats seeking to replace him, all of whom want to run William Jennings Bryan's fourth campaign. Bryan lost three times, but today they are all prairie populists, even the fellow from Boston's Beacon Hill, inveighing against ``special interests.'' That category, although capacious, does not encompass trial lawyers, teachers unions and hundreds of other Democratic clients, including Iowa beneficiaries of ethanol subsidies.

But if the president is to win a second term, and if it is to be worth winning, he must begin again to speak plainly and accurately, not just less foolishly than the make-believe Bryans.